<!doctype html>
<html>
<body>
<canvas id="can" width="400" height="400" style="background:Black"></canvas>
<script>
    var sn=[42,41],dz=43,fx=1,n,ctx=document.getElementById("can").getContext("2d");
    function draw(t,c){
        ctx.fillStyle=c;
        ctx.fillRect(t%20*20+1,~~(t/20)*20+1,18,18);
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        sn.unshift(n=sn[0]+fx);
        if(sn.indexOf(n,1)>0 || n<0||n>399||fx==1&&n%20==0||fx==-1&&n%20==19) return alert("GAME OVER");
        draw(n,"Lime");
        if(n==dz){
            while(sn.indexOf(dz=~~(Math.random()*400))>=0);
            draw(dz,"Yellow");
        }else
            draw(sn.pop(),"Black");
        setTimeout(arguments.callee,130);
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</script>
</body>
</html>